A conventional drive control system for a motor may be equipped with a tacho-generator connected to the motor shaft for providing an electric signal. This signal may be used as a feed-back signal and applied to a driver circuit for controlling the rate of rotation or angular velocity of the motor in an attempt to increase the operating stability and precision of the motor. The tacho-generator can, however, be a significant load for the motor system and may seriously cause a drop of response thereby to an input drive signal.